The present invention relates to a seat belt retractor, and particularly relates to an electrically lockable seat belt retractor.
Electrically actuated seat belt retractors are known. In such a seat belt retractor, an electrically actuated locking mechanism blocks rotation of a spool on which seat belt webbing is wound to help protect a vehicle occupant in the event of a vehicle collision. The known vehicle seat belt systems which have electrically actuated seat belt retractors typically utilize a single, centrally located collision sensor and an associated controller. The sensor and controller sense a condition indicative of a vehicle collision and send an electrical signal to each of the electrically actuated seat belt retractors in the vehicle to cause the retractors to lock.
The present invention is a seat belt retractor comprising a frame, a seat belt webbing spool rotatably mounted in the frame, and actuator means for locking the seat belt webbing spool against rotation in at least one direction in the frame. The actuator means is mounted to the frame. Accelerometer means provides an electrical output signal indicative of vehicle deceleration. The accelerometer means is mounted on the frame. Controller means monitors the electrical output signal and causes the actuator to lock the seat belt webbing spool against rotation in the one direction upon the occurrence of a predetermined amount of vehicle deceleration. The controller means is mounted on the frame.
The present invention further contemplates that a seat belt retractor constructed according to the present invention be used as a part of a vehicle occupant protection apparatus. The apparatus includes an inflatable vehicle occupant protection device, such as an air bag, and/or one or more additional seat belt retractors constructed in accordance with the present invention.
The foregoing and other features of the present invention will becomes apparent to one skilled in the art to which the present invention relates upon consideration of the following description of the invention with reference to the accompanying drawings, wherein:
FIG. 1 is a schematic illustration of a vehicle seat belt system having a seat belt retractor constructed in accordance with the present invention;
FIG. 2 is a perspective view of the seat belt retractor of FIG. 1;
FIG. 3 is a fragmentary schematic illustration of a vehicle equipped with the seat belt retractor of FIG. 2;
FIG. 4 is a view similar to FIG. 2 showing a second embodiment of a seat belt retractor constructed in accordance with present invention; and
FIG. 5 is a view similar to FIG. 4 showing a third embodiment of a seat belt retractor constructed in accordance with present invention.